Many large mobile and/or stationary machines such as mining trucks, locomotives, marine applications, pumps, compressors, generators, and the like have recently begun using alternative fuels, alone or in conjunction with traditional fuels, to power their internal combustion engines. An example of an alternative fuel is natural gas, which may be in the form of liquefied natural gas (LNG) or compressed natural gas (CNG), and which may provide cost and/or environmental advantages over more traditional fossil fuel sources. Because natural gas is in a highly voluminous and gaseous phase under normal environmental conditions, the natural gas is typically converted into a highly compressed state or condensed into a liquefied phase to simplify handling, transportation, and storage. The conversion of natural gas to these compressed or liquefied forms requires that the natural gas be maintained in a highly pressurized state at cryogenically low temperatures, for example, on the order of −160° C.
To store and utilize cooled natural gas in compressed or liquefied forms onboard mobile machines, specialized storage tanks and fuel delivery systems are required. This equipment may include a double-walled cryogenic tank and a pump for delivering the LNG or CNG to the internal combustion engine for combustion. The pump may be specially configured to maintain the cryogenic temperatures within the tank so that the LNG does not prematurely evaporate. One example of a cryogenic pump for pumping cryogenic fluids such as LNG from a cryogenic tank is described in co-pending U.S. Pat. No. 6,481,218 (“the '218 application”) titled Pump System for Delivering Cryogenic Liquids and assigned Linde Gas Aktiengesellschaft. The '218 patent describes a plurality of pumping elements that can be disposed in a container communicating with a storage tank that can receive cryogenic liquids. The pumping elements can be activated in a reciprocal manner to deliver the cryogenic liquid to an application while maintaining the liquid state. In an embodiment, the '218 application describes that the cryogenic liquid may be used as a fuel source. The present disclosure is also directed to a cryogenic pump for delivering a cryogenic liquids from a storage to an application.